1. Field of the Invention
The invention relates to a permanent whipstock for use downhole in a wellbore.
2. Prior Art
For many years whipstock assemblies have been used to deflect drillstrings around obstructions in a formation or in a previously completed casing. Whipstock have been used with great success, however, normally require several trips and a number of separate parts.
Generally, to employ a whipstock assembly to deflect a drillstring, the whipstock assembly must be supported. Supports for whipstocks are most commonly in the form of packers. Packers have been designed in many different ways over the years and have performed their intended function satisfactorily but most require they be run in the hole separately or that complex apparati and multiple steps be used to set the packer and whipstock on the same run-in of the workstring. Examples of such packers and whipstock/packer assemblies include Baker DW-1 packer/anchor and whipstock assembly.
While the above methods and apparati for supporting a whipstock are functional, they are expensive, either because of complexity or because of the need to remove the workstring. Therefore a need exists for a permanent whipstock assembly which does not require a packer and which can be fully and securely set in one run-in of the workstring.